zero turn is the only way to go. you can get by with only going around the pastures maybe once a month after the spring greening and with the obstacles you have anything else will be work
I have 8 acres and before I got my tractor and bush hog I went and introduced myself to the neighbor with a tractor and bush hog and he came over and cut my pastures for a couple of beers and a steak dinner
once the summer hit I cut it with my zero turn
a little bouncy but I got it done